Flush valve and flush valve assembly

ABSTRACT

A flush valve assembly, comprising a flush valve comprising a flush valve body extending from a flush valve inlet to a flush valve outlet; a flapper cover having a top face and a bottom face and a front and a back; and a flush actuator comprising a lift rod; wherein the bottom face of the flapper cover is configured to enclose the flush valve inlet; and wherein the lift rod is coupled to the top face of the flapper cover and is configured to lift the flapper cover to partially open the flush valve and to fully open the flush valve.

The invention relates to flush valves and flush valve assemblies, suitable for gravity flush toilets for removal or human and other waste.

BACKGROUND

Gravity flush toilets for removing waste, such as human waste, generally have two main parts, a tank and a bowl. A tank is typically position over the bowl and contains water that is used to initiate flushing of waste from the bowl to a sewage line, and for refilling the bowl with fresh water after a flush. A tank may comprise one or more flush valves, which when opened, remains open until a predetermined amount of flush water flows from the tank to the bowl through the valve to provide a flush. A fill valve provides water from a supply water line to refill the tank.

Certain trends, such as urbanization, resulting in smaller living spaces, provide incentive to provide smaller appliances and equipment, including toilets. Accordingly, desired are smaller toilets having smaller toilet tanks, which may still provide a required flush. Smaller toilet tanks require new flush assemblies. The present invention provides flush valve assemblies that address this and other needs.

SUMMARY OF THE INVENTION

Disclosed is a flush valve assembly, comprising a flush valve comprising a flush valve body extending from a flush valve inlet to a flush valve outlet; a flapper cover having a top face and a bottom face; and a flush actuator comprising a lift rod; wherein the bottom face of the flapper cover is configured to enclose the flush valve inlet; and wherein the lift rod is coupled to the top face of the flapper cover and is configured to lift the flapper cover to partially open the flush valve and/or to fully open the flush valve.

Also disclosed is a flush valve, comprising a flush valve body extending from a flush valve inlet to a flush valve outlet, wherein the flush valve inlet comprises a lead-in lip.

Also disclosed flush valve, comprising a flush valve body extending from a flush valve inlet to a flush valve outlet, wherein the valve inlet is non-circular.

Also disclosed is a flush valve, comprising a flush valve body extending from a flush valve inlet to a flush valve outlet, wherein the flush valve body is non-symmetrical.

These and other features, aspects, and advantages of the disclosure will be apparent from a reading of the following detailed description together with the accompanying drawings, which are briefly described below. The invention includes any combination of two, three, four, or more of the disclosed embodiments as well as combinations of any two, three, four, or more features or elements set forth in this disclosure, regardless of whether such features or elements are expressly combined in a specific embodiment description herein. This disclosure is intended to be read such that any separable features or elements of the disclosed invention, in any of its various aspects and embodiments, should be viewed as intended to be combinable unless the context clearly dictates otherwise. Other aspects and advantages of the present invention will become apparent from the following.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure described herein is illustrated by way of example and not by way of limitation in the accompanying figures. For simplicity and clarity of illustration, features illustrated in the figures are not necessarily drawn to scale. For example, the dimensions of some features may be exaggerated relative to other features for clarity. Further, where considered appropriate, reference labels have been repeated among the figures to indicate corresponding or analogous elements.

FIG. 1A depicts a perspective top, front view of a flush valve assembly according to an embodiment.

FIG. 1B depicts a cross-section view of a flush valve assembly according to an embodiment.

FIG. 2 represents an embodiment of a flush valve assembly associated with a hydraulic cylinder.

FIG. 3A, FIG. 3B, and FIG. 3C show an elliptical flush valve body according to an embodiment, in a perspective view, top view and side view, respectively.

FIG. 4 depicts a cross-section view of a flush valve body containing a lead-in lip, according to an embodiment.

FIG. 5A and FIG. 5B depict a side view and top view of a flush valve body, respectively, containing a lead-in lip, according to an embodiment.

FIG. 6A, FIG. 6B, FIG. 6C, and FIG. 6D show a flush valve assembly from left side, right side, back, and front views, respectively, according to an embodiment.

FIG. 6E, FIG. 6F, and FIG. 6G show a cross-section view of a flush valve in various stages of valve opening, according to an embodiment.

DETAILED DISCLOSURE

The present apparatus is suitable as a gravity-type flush valve assembly designed to be useful for toilets and toilet assemblies having a toilet tank for gravity/siphon-based flushing. The flush valve assembly components may be formed of a polymeric material, such as a moldable thermoplastic, and constructed to have an interior surface that defines a flow path from an upper inlet end to a lower outlet end thereby allowing flush water to pass through the flush valve when open.

In some embodiments, the flush valve is suitable for a toilet. In other embodiments, the flush valve may be suitable for a urinal, garden water features, fish ponds, etc. The flush valve is suitable for use in small tanks, for example in-wall tanks.

The valve comprises a valve body defining an interior flow path extending from a valve inlet to a valve outlet. Fluid may flow through the valve from inlet to outlet when the valve is open; fluid may not flow through the valve when the valve is closed. The flapper cover may have a generally planar shape, having a top face and a bottom face. The flapper bottom face encloses and is in contact with the valve inlet in a closed position. In a closed position, the flapper cover provides a seal so as to not allow any fluid flow through the valve. The seal is where a flapper cover bottom face is in contact with a flush valve inlet in a closed position. The seal may also be called a “sealing surface” and will have a shape corresponding to the flush valve inlet.

The flapper cover is coupled to a flush actuator which comprises a lift rod. The lift rod may be configured to partially lift the flapper cover in order to partially open the flush valve. The lift rod may also be configured to fully lift the flapper cover in order to fully open the flush valve. The term “partially lift” or “partially open” means that part of the flapper cover is lifted away from the valve inlet while part of the flapper cover remains in contact with the valve inlet. The term “fully lift” or “fully open” means that the flapper cover is completely removed from and not in contact the valve inlet. In some embodiments, the lift rod may be rigid. In other embodiments, the lift rod may be flexible or partly flexible.

In some embodiments, after a partial opening of the flush valve, the lift rod may be configured to lower the flapper cover directly to the closed position to close the valve. In some embodiments, after a partial opening of the flush valve, the lift rod may be configured to further lift the flapper cover so that the valve is fully opened. Accordingly, the present assembly may provide multiple toilet flush volumes. Multiple flush volumes may correspond to a flapper cover “partial lift” and “full lift”. A user may choose for instance a “full flush” of about 1.6 gallons (about 6 liters) of water to eliminate solid waste or a “partial flush” (short flush) of a lower volume or water, for example about 1.1 gallons (about 4 liters), for the removal of liquid waste. Multiple flush volumes are described for example in US2010/0043130.

After a flapper cover is fully lifted off the valve inlet, the lift rod may be configured to further lift the flapper cover to provide more “head space” above the open inlet to provide for a greater fluid flow into the inlet. In some embodiments, the flapper cover may be lifted to a position where it is substantially parallel to the flush valve inlet and substantially perpendicular to the lift rod. In this embodiment, a substantially symmetrical, substantially cylinder-shaped full head space above the inlet may be provided. In some embodiments, a substantially symmetrical, full head space provides a full flush. In some embodiments, the distance of the flapper cover closed position to a position wherein it is substantially parallel to the valve inlet is from any of about 2.5 cm, about 2.6 cm, about 2.7 cm, about 2.8 cm, about 2.9 cm, about 3.0 cm, about 3.1 cm, about 3.2 cm, about 3.3 cm, about 3.4 cm, about 3.5 cm, about 3.6 cm, about 3.7 cm or about 3.8 cm to any of about 3.9 cm, about 4.0 cm, about 4.1 cm, about 4.2 cm, about 4.3 cm, about 4.4 cm, about 4.5 cm, about 4.6 cm, about 4.7 cm, about 4.8 cm, about 4.9 cm, about 5.0 cm, about 5.1 cm or about 5.2 cm.

In some embodiments, a length of a lift rod may be from any of about 10 cm, about 12 cm, about 14 cm, about 16 cm or about 18 cm to any of about 20 cm, about 22 cm, about 24 cm, about 26 cm, about 28 cm or about 30 cm. In some embodiments, a lift rod may have a width of from any of about 0.5 cm, about 0.7 cm, about 0.9 cm, about 1.1 cm, about 1.3 cm or about 1.5 cm to any of about 1.7 cm, about 1.9 cm, about 2.1 cm, about 2.3 cm, about 2.5 cm or about 2.7 cm.

In certain embodiments, a flush valve body may extend from a flush valve inlet to a flush valve outlet a distance of from any of about 3 cm, about 4 cm, about 5 cm or about 6 cm to any of about 7 cm, about 8 cm, about 9 cm, about 10 cm or about 11 cm.

In some embodiments, the flapper cover may be adapted to be a “peelable” or “peel-away” cover. The flapper cover may be configured to open (lift) from the front of the cover along the edge towards the back of the cover in a peeling fashion. A peel-away flapper cover may be flexible, that is, the cover may comprise a flexible portion. A flexible flapper cover may comprise a flexible portion and a rigid portion. In some embodiments, a flapper cover flexible portion comprises an elastomer, rubber, silicone or other flexible polymer. The term “flexible” encompasses “partly-flexible”. In some embodiments, the bottom face of the flapper cover consists essentially of a flexible portion. In some embodiments, the flapper cover may comprise a continuous flexible bottom face and a top face comprising a rigid plate or plates. Rigid plates may be segmented or discontinuous. In other embodiments, the flapper cover may comprise a front flexible portion and a back rigid portion. Peelable flapper covers are described for example in US2015/0197928. In some embodiments, when a flapper cover is partially lifted to partially open the flush valve, the valve may be considered “partially peeled open” or the flapper cover may be considered “partially peeled off” the valve inlet.

In some embodiments, a partial flapper cover lift may mean that about 50% of the flapper cover bottom face is lifted off the valve inlet from the front towards the back and about 50% of the flapper cover bottom face remains seated on the valve inlet with a partial seal intact. This refers to the diameter of the flapper cover bottom face from front to back. In other embodiments, a partial flapper cover lift may mean about 80%, about 75%, about 70%, about 65%, about 60%, about 55%, about 45%, about 40%, about 35%, about 30%, about 25% or about 20% of the flapper cover bottom face is lifted off the valve inlet from front to back with the remainder of the bottom face remaining seated on the valve inlet with a partial seal intact.

In certain embodiments, disclosed is a flush valve having a flush valve body extending from a flush valve inlet to a flush valve outlet, wherein the valve inlet is non-circular. A circular valve inlet has an inlet which is substantially circular from a top view (like the top view of a cylinder), that is to say, the seal of a closed valve is substantially circular. In some embodiments, a non-circular valve inlet may be elliptical. Flush valves having non-circular valve inlets may have circular or non-circular outlets and/or circular or non-circular bodies. Flush valves having non-circular valve inlets may have correspondingly non-circular shaped flapper covers.

In certain embodiments, non-circular flush valve inlet shapes may include triangular, rectangular, square, oval, oblong, ovate, elliptic (elliptical), obovate, cuneate, deltoid and orbicular, among others. Also disclosed are flapper covers having corresponding shapes configured to form a seal when placed over a flush valve inlet with the valve in a closed position. Triangular and rectangular shapes include those having one or more rounded angles.

In some embodiments, an area of a flush valve inlet may be from any of about 45 cm², about 47 cm², about 50 cm², about 53 cm² or about 56 cm² to any of about 59 cm², about 62 cm², about 65 cm², about 68 cm², about 71 cm², about 74 cm², about 77 cm² or about 80 cm². A surface area of a flapper cover bottom or top face may have slightly larger surface areas or about the same surface areas.

In some embodiments, the flush valve assembly may comprise a back-flow preventer mechanism, for example a back-flow preventer mechanism as described in US2015/0197928. Back-flow preventer mechanisms include hold-down linkage mechanisms, hook and catch mechanisms, poppet mechanisms, and check valves. An advantage of the present flush valve assembly is that a back-flow preventer mechanism may not be required as the lift rod itself may hold the flapper cover in a closed position and prevent any back-flow.

The flush valve assembly may be associated with other elements, for instance an overflow tube, a fill valve, a float, a cleaning injection system, and the like.

The flush actuator comprising a lift rod may be powered via a motor, for instance an electric gear motor, a hydraulic cylinder, a manual lever, a push button, or a combination thereof. The present flapper covers may be lifted from the front towards the back, for instance in a peelable fashion. Thus, the flush valve assemblies require less energy to lift and open the flapper cover, allowing the elements of the assemblies to undergo less stress and allowing them to last longer.

In some embodiments, the fluid flow path from flush valve body inlet to outlet is substantially uniform, that is, the interior shape of the valve inlet body from inlet to outlet, defining the flow path, is substantially uniform. In other embodiments, an inlet may be “radiused” or comprise a “lead-in angle”. In some embodiments, a portion of the flush valve body may be downwardly-tapered from inlet to outlet, providing a decreasing valve body diameter along the flow path, that is, providing a decreasing liquid volume flow path (decreasing flow path). In some embodiments, a flush valve body may comprise both a radiused inlet and a downwardly-tapered valve body. The terms “radiused” and “downwardly-tapered” may mean linearly radiused or tapered or, may mean non-linearly radiused or tapered. Flush valves having a radiused inlet and tapered bodies are described for example in U.S. Pat. Nos. 6,715,162, 6,728,975 and 6,901,610 and US2014/0090158.

In some embodiments, a flush valve body that is downwardly-tapered may be generally symmetrical, providing a generally symmetrical decreasing flow path. In other embodiments, a flush valve body that is downwardly-tapered may be non-symmetrical, providing a non-symmetrical decreasing flow path. A flush valve body will also have a front and a back, corresponding to front and a back sections of a flapper cover. Non-symmetrical tapering may mean a flush valve body front or back is more tapered than the other. Non-symmetrical tapering may mean a liquid flow path is longer in a flush valve body front or back than the other. Another way to describe a non-symmetrical downwardly-tapered flush valve body is that a valve outlet center is not aligned with a valve inlet center along an x-y plane or along an x-z plane. A “center” means a mid-point along a longest diameter. A non-symmetrical flush valve body may be linearly or non-linearly downwardly-tapered. In some embodiments, a non-symmetrical flush valve body may comprise a circular or a non-circular inlet.

A non-symmetrical flush valve body may comprise a symmetrical portion and a non-symmetrical portion. For instance, a flush valve body may comprise a symmetrical, substantially circular (substantially cylindrical) outlet portion and a non-symmetrical downwardly-tapered inlet portion.

Also disclosed herein is a flush valve comprising a flush valve body extending from a flush valve inlet to a flush valve outlet, wherein the flush valve inlet comprises a lead-in lip. A “lead-in lip” may be described as an inverted geometry on the outside of the sealing surface. A lead-in lip may help direct the flow of water up and over a flush valve inlet.

In some embodiments, an area of a flush valve outlet may be the same or similar to a flush valve inlet. In other embodiments, an area of a flush valve outlet may be smaller than that of a flush valve inlet, for instance when the valve body is downwardly-tapered. For instance, in some embodiments, an area of a flush valve outlet may be from any of about 10 cm², about 12 cm², about 14 cm², about 16 cm² or about 18 cm² to any of about 20 cm², about 22 cm², about 24 cm², about 26 cm², about 28 cm², about 30 cm² or about 32 cm².

Flush valve assemblies having a flush valve having a circular inlet may in general also comprise a circular-shaped flapper cover. Flush valve assemblies having a flush valve having a non-circular shaped inlet may in general also comprise a correspondingly non-circular shaped flapper cover. For instance, a flush valve assembly having a flush valve having an elliptical valve inlet may comprise an elliptical flapper cover. As discussed, in some embodiments, the flapper cover is configured to lift and open the valve from the front of the cover towards the flapper cover back. The flapper cover comprises a front section (the front) and a back section (the back), which sections meet at an arbitrary point along a diameter of the flapper cover. The arbitrary point may be at a point midway along a diameter, or at any point along a diameter or at any line bisecting the flapper cover. A flush valve body will have corresponding front and back sections.

In some embodiments, a present flapper cover having a triangular, ovate, obovate, cuneate or deltoid or similar shape, will comprise a narrow end and a wide end. In some embodiments, a flapper cover front will comprise the narrow end and a flapper cover back will comprise the wide end. In other embodiments, a flapper cover front will comprise the wide end and a flapper cover back will comprise the narrow end.

In certain embodiments, the flapper cover may by be coupled to the lift rod via hinged arms disposed on the top face. Hinged arms may be adapted to provide a peelable flapper cover. Hinged arms disposed on a flapper cover are described in US2015/0197928.

In other embodiments, the flapper cover may be coupled to the lift rod via a multi-arm linkage. In an embodiment, a multi-arm linkage comprises a pivot arm coupled to the flapper cover top face towards the flapper front. In some examples, the pivot arm may be curved. In certain embodiments, the pivot arm may be curved inward toward the flapper cover center, or vice versa. A flapper cover “center” means a mid-point along a diameter, for instance along a longest diameter. The pivot arm may also comprise one or more joints around which the arm may rotate or flex. A multi-arm linkage may comprise one or more slotted elements adapted to allow movement of other elements, for example sliding or flex motion of one or more arms when flapper cover is in motion—that is, being lifted or lowered. The slotted elements may aid in a flapper cover lifting, lowering, and/or a peeling motion. Elements may be coupled to slotted elements via a slot-and-pin arrangement. Slot-and-pin attachments allow for movement of the pin within the slot. The term “multi-arm” may mean 2, 3, 4, 5 or more arm-like elements. A “joint” may comprise a pin-hole feature, a slot-pin feature, and the like.

In some embodiments, parts of a multi-arm linkage and a lift arm may be rigid. In other embodiments, parts of a multi-arm linkage and a lift arm may be flexible. Parts of a multi-arm linkage and a lift arm may comprise one or more of a thermoplastic, an elastomer, a rubber, silicone or other flexible polymer.

The pivot arm may be coupled to the lift rod via a substantially horizontal arm extending from the rod. The substantially horizontal arm may be slotted. The lift rod may be coupled to a substantially vertical arm extending from the flapper cover top face, for instance via a slot on the lift rod and a pin on the vertical arm or vice versa. The vertical arm (and lift rod) may be located towards the center of the flapper cover top face. The flapper cover top face back may comprise an element adapted to couple with an arm extending from the front of the flapper, which arrangement may aid a peeling or an initial lift motion. The arm extending from the flapper cover front may be coupled to the element on the flapper cover back via a slot-and-pin attachment.

In some embodiments, the lift rod is coupled to the flapper cover towards the center of the cover. The lift rod may be associated with an element to guide its lifting and lowering motion. In some embodiments, the “guide element” may comprise a tubular body, within which the lift rod is disposed. The lift rod is in some embodiments substantially perpendicular with the flapper cover.

In some embodiments, the assembly comprises an element configured to provide an “end point” or “stop” for the lifting flapper cover. In some embodiments, this “first stop element” is a ring or is substantially ring-like. A first stop element may be supported by and coupled to the flush valve body, and may also be coupled to the guide element. A first stop element may be coupled to the flush valve body via one or more vertical arms. The vertical arms may be supported by a platform extending from the flush valve body, or from a platform about the valve inlet. In some embodiments, the first stop element is supported by and coupled to the flapper cover top face via one or more arms. The first stop element may be adapted to encourage the lifting flapper cover to be placed in a position where it is substantially parallel with the flush valve inlet and substantially perpendicular with the lift rod. In this embodiment, a head space above the inlet may be provided. In some embodiments, the top face of the flapper cover may comprise an element configured to engage the first stop element as the flapper cover is lifted. This “second stop element” may be disposed towards the front of the flapper cover top face. The second stop element and/or the first stop element may comprise a feature to engage the other, for example a gear-like groove-and-ridge arrangement on one or the other or on both. A ridge is adapted to fit into and couple to a groove.

In some embodiments, the flapper cover is configured to partially lift or peel off from the front of the flapper cover towards the back. The flapper cover may be directly lowered to a closed position or further lifted to a fully open position. The flapper cover may be further lifted to an end-point or stopped position where it is substantially parallel with the flush valve inlet and substantially perpendicular with the lift rod, thus providing a maximum fluid head space above the valve inlet.

In some embodiments, a multi-arm linkage may be configured to attach to both a front and a back of a flapper cover. In such embodiments, as a lift rod is actuated, it may partially lift or peel the flapper cover from both the front and back to partially open the flush valve. The flapper cover may be directly lowered to a closed position or further lifted to a fully open position. The flapper cover may be further lifted to an end-point or stopped position where it is substantially parallel with the flush valve inlet and substantially perpendicular with the lift rod, thus providing a maximum fluid head space above the valve inlet. In such an embodiment, there may be two first and second stop elements. In other embodiments, a multi-arm linkage may be configured to attach to multiple points around a flapper cover top face, thereby adapted to partially lift or peel the flapper cover from around a partial or entire perimeter of the flapper cover.

FIG. 1A shows a top, front perspective view of flush valve assembly 100 according to an embodiment. Flapper cover 101 is shown in a closed position over valve inlet 102, with the bottom face of flapper cover 101 enclosing valve inlet 102. Valve outlet 103 is at the bottom of valve body 104. Flapper cover 101 contains a flexible portion 105 and rigid portions 106. Rigid moveable lift rod 107 is coupled to the flapper cover top face via multi-arm linkage 108. Lift rod 107 is disposed within tubular guide element 109. Visible towards the front of the flapper cover are pivot arm 110 and second stop element 111. Second stop element 111 is adapted to engage ring-like first stop element 112 situated above the valve inlet. As lift rod 107 lifts upward, multi-arm linkage 108 lifts the flapper cover front end in a “peeling motion” while the flapper cover rear end remains sealed to valve inlet 102. As the lift rod continues to lift, the first and second stop elements engage, and the flapper cover rear end is lifted and the flapper cover is encouraged to enter into a position where it is substantially parallel with the valve inlet and substantially perpendicular with the lift rod. First stop element 112 is coupled to the valve body and guide element via vertical arms 113.

FIG. 1B is a side cut-away view of flush valve assembly 100 according to an embodiment that provides a more detailed view of multi-arm linkage 108. Flapper cover 101 is in a closed position. Shown are curved pivot arm 110 containing joint 114 that allows the pivot arm to flex as it is moved by lift rod 107. Pivot arm 110 is coupled to the front of the flapper cover top face and to horizontal arm 115 extending from lift rod 107. Pivot arm 110 is connected to horizontal arm 115 via joint 116 around which it can rotate. Lift rod 107 contains a slot coupled to vertical arm 117 extending from the flapper cover top face via a pin on the vertical arm. First stop element 112 is supported by vertical arms 113 above the valve inlet. Second stop element 111 is coupled to the flapper cover top face front. The flapper cover top face back is coupled to element 118 adapted to couple with arm 119 extending from the front of the flapper, which arrangement may aid a peeling or an initial lift motion. Arm 119 extending from the flapper cover front may be coupled to element 118 on the flapper cover back via a slot-and-pin attachment.

FIG. 2 shows a flush valve assembly 200 according to an embodiment wherein the assembly is associated with a hydraulic cylinder 201 configured for moving lift rod 202 to lift and lower flapper cover 203 (shown in a partially lifted position). First stop element 205 contains a feature 204 adapted to engage second stop element 206. In this instance, feature 204 is a rounded element adapted to engage with curved second stop element 206. In other embodiments, the lift rod may be powered with an electric motor, with a manual lever, or by a combination of these methods.

FIG. 3A, FIG. 3B and FIG. 3C depict an elliptical, non-circular flush valve body 300 in a perspective, top and side views. An inlet portion 301 of flush valve body 304 is non-linearly downwardly-tapered from inlet 302 towards outlet 303. Flush valve body 300 of FIG. 3A, FIG. 3B and FIG. 3C is generally symmetrical.

FIG. 4 shows a side cut-away view of a flush valve body 400 according to an embodiment, wherein valve body 404 comprises a lead-in lip 405 around the entirety of the inlet. The flush valve body is non-linearly downwardly-tapered along a portion 401 from inlet 402 to outlet 403. In this embodiment, inlet 402 and outlet 403 have an elliptical shape. Also visible is multi-arm linkage 408, second stop element 409, flapper cover 406 and a lift rod 407. Flapper cover 406 comprises a flexible portion 410 and rigid portions 411. Multi-arm linkage 408 contains arm 413 extending from flapper cover front to couple with element 412 on flapper cover back via a slot-and-pin arrangement. In this embodiment, multi-arm linkage 408 will contain corresponding features 412 and 413 on left and right sides of lift arm 407. Flapper cover 406 comprises an elliptical shape. In the embodiment of FIG. 4, lead-in lip 405 extends downward about 13% of the distance from valve inlet 402 to valve outlet 403. In other embodiments, a lead-in lip may extend downward from any of about 5%, about 7%, about 9%, about 11%, about 13%, about 15%, about 17% or about 19% to any of about 21%, about 23%, about 25%, about 27%, about 29% or about 31% of the distance from a valve inlet to a valve outlet. Flush valve body 404 is generally symmetrical.

FIG. 5A and FIG. 5B depict a side view and top view of a flush valve body 500 according to an embodiment. Flush valve body 500 comprises a lead-in lip 501 extending outward and downward around the entirety of inlet 502. Valve body 500 extends from inlet 502 to outlet 503. The valve body is non-linearly downwardly-tapered and is non-symmetrical. Valve body front 505 is more tapered than back 506 and the front therefore provides a longer liquid flow path. FIG. 5A and FIG. 5B show a valve outlet center 507 that is not aligned with valve inlet center 508 along an x-z plane or along an x-y plane, respectively. Valve body 500 comprises a substantially symmetrical, cylindrical outlet portion 504 and a non-symmetrical downwardly-tapered inlet portion 509.

FIG. 6A, FIG. 6B, FIG. 6C, and FIG. 6D show left side, right side, back, and front views of flush valve assembly 600, respectively, according to an embodiment. Flush valve assembly 600 contains flush valve body 400 of FIG. 4. Flapper cover 406 is in a closed position enclosing flush valve inlet 402. Valve body 404 extends from inlet 402 to outlet 403. Flapper cover 406 contains flexible portion 410 and rigid portions 411. Flapper cover 406, inlet 402, and outlet 403 comprise an elliptical shape. Flush valve assembly comprises multi-arm linkage 408 coupled to flapper cover 401 top face and lift rod 407. Valve body 404 comprises lead-in lip 405. Multi-arm linkage 408 contains second stop element 409. Assembly 600 contains elliptical, ring-shaped first stop element 602 containing rod-shaped feature 603 configured to engage upwardly-curved second stop element 409. Lift rod 407 is disposed in guide element 601. Multi-arm linkage 408 comprises complimentary features on either side of lift arm 407.

FIG. 6E, FIG. 6F, and FIG. 6G show cross-section, left side views of flush valve assembly 600 in various stages of flapper cover 406 being lifted, according to some embodiments. In FIG. 6E, flapper cover 406 is partially lifted in a peeling motion from front to back, partially opening the flush valve. As flapper cover 406 is lifted, arm 413 is able to rotatably move relative to feature 412 via a slot-and-pin coupling. Features 412 and 413 are present on left and right sides of flapper cover 406. Flexible portion 410 allows for the peeling motion. FIG. 6F shows second stop element 409 engaging feature 603 as lift rod 407 is further lifted. As second stop element 409 engages feature 603, multi-arm linkage 408 is encouraged to lift flapper cover 406 from the back face. Flush valve cover 406 may be lowered to enclose inlet 402 to close the flush valve from a partially opened position to provide a partial low volume flush. Alternatively, lift rod 407 may continue to lift flapper cover 406 to provide a substantially symmetrical, substantially cylinder-shaped full head space 604 above inlet 402 as depicted in FIG. 6G. A full head space above valve inlet 402 may provide for a full flush. Flapper cover 406 is substantially parallel with valve inlet 402 and substantially perpendicular to lift rod 407 in FIG. 6G.

Gravity-powered toilets fall generally into two categories: wash down and siphonic. In a wash-down toilet, the water level within the bowl of the toilet remains relatively constant at all times. When a flush cycle is initiated, water flows from the tank and spills into the bowl. This causes a rapid rise in water level and the excess water spills over the weir of the trapway, carrying liquid and solid waste along with it. At the conclusion of the flush cycle, the water level in the bowl naturally returns to the equilibrium level determined by the height of the weir.

In a siphonic toilet, the trapway and other hydraulic channels are designed such that a siphon is initiated in the trapway upon addition of water to the bowl. The siphon tube itself is an upside down curved, generally U-shaped tube that draws water from the toilet bowl to the wastewater line. When the flush cycle is initiated, water flows into the bowl and spills over the weir in the trapway faster than it can exit the outlet to the sewer line. Sufficient air is eventually removed from the down leg of the trapway to initiate a siphon, which in turn pulls the remaining water by vacuum out of the bowl. The water level in the bowl when the siphon breaks is consequently well below the level of the weir, and a separate mechanism needs to be provided to refill the bowl of the toilet at the end of a siphonic flush cycle to reestablish the original water level and protective “seal” against back flow of sewer gas.

Siphonic and wash-down toilets each have inherent advantages and disadvantages. Wash-down toilets can function with larger trapways than siphonic toilets, but generally require a smaller amount of pre-flush water in the bowl to achieve the 100:1 dilution level required by plumbing codes in most countries (That is, 99% of the pre-flush water volume in the bowl must be removed from the bowl and replaced with fresh water during the flush cycle). This small pre-flush volume manifests itself as a small “water spot.” The water spot, or surface area of the pre-flush water in the bowl, plays an important role in maintaining the cleanliness of a toilet and reducing odors. A large water spot increases the probability that waste matter will contact water before contacting the ceramic surface of the toilet. This reduces adhesion of waste matter to the ceramic surface making it easier for the toilet to clean itself via the flush cycle. Wash-down toilets with their small water spots therefore frequently require manual cleaning of the bowl after use. The adhesion of waste material above the water line also leads to a greater level of unpleasant smell during use.

Siphonic toilets, due to the requirement that most of the air be removed from the down leg of the trapway in order to initiate a siphon, tend to have smaller trapways which can result in clogging. Siphonic toilets have the advantage of being able to function with a greater pre-flush water volume in the bowl and greater water spot. This is possible because the siphon action pulls the majority of the pre-flush water volume from the bowl at the end of the flush cycle. As the tank refills, a portion of the refill water is directed into the bowl to return the pre-flush water volume to its original level. In this manner, the 100:1 dilution level required by many plumbing codes is achieved even though the starting volume of water in the bowl is significantly higher relative to the flush water exited from the tank. In the North American markets, siphonic toilets have gained widespread acceptance and are now viewed as the standard, accepted form of toilet. In European markets, wash-down toilets are still more accepted and popular. Whereas both versions are common in the Asian markets.

As described in US2010/0043130, gravity-powered siphonic toilets generally fall into three categories, depending on the design of the hydraulic channels used to achieve the flushing action. These categories are: non-jetted, rim jetted, and direct jetted.

In non-jetted bowls, all of the flush water exits the tank and enters the bowl through a “tank inlet area” in the bowl and flows through a manifold into the rim channel. The water is dispersed around the perimeter of the bowl via a series of holes positioned underneath the rim. Some of the holes are designed to be larger in size to allow greater flow of water into the bowl. A relatively high flow rate is needed to spill water over the weir of the trapway rapidly enough to displace sufficient air in the down leg and initiate the siphon. Non-jetted bowls typically have adequate to good performance with respect to cleansing of the bowl and replenishment of the pre-flush water, but are relatively poor in performance in terms of bulk removal. The feed of water to the trapway is inefficient and turbulent, which makes it more difficult to sufficiently fill the down leg of the trapway and initiate a strong siphon. Consequently, the trapway of a non-jetted toilet is typically smaller in diameter and contains bends and constrictions designed to impede flow of water. Without the smaller size, bends, and constrictions, a strong siphon would not be achieved. Unfortunately, the smaller size, bends, and constrictions result in poor performance in terms of bulk waste removal and frequent clogging, conditions that are extremely dissatisfying to end users.

Designers and engineers of toilets have improved the bulk waste removal of siphonic toilets by incorporating “jets.” In a rim-jetted toilet bowl, the flush water exits the tank through the tank inlet area and flows through a manifold into the rim channel. A portion of the water is dispersed around the perimeter of the bowl via a series of holes positioned underneath the rim. The remaining portion of water flows through a jet channel positioned at the front of the rim. This jet channel connects the rim channel to a jet opening positioned in the sump of the bowl. The jet opening is sized and positioned to send a powerful stream of water directly at the opening of the trapway. When water flows through the jet opening, it serves to fill the trapway more efficiently and rapidly than can be achieved in a non-jetted bowl. This more energetic and rapid flow of water to the trapway enables toilets to be designed with larger trapway diameters and fewer bends and constrictions, which, in turn, improves the performance in bulk waste removal relative to non-jetted bowls. Although a smaller volume of water flows out of the rim of a rim-jetted toilet, the bowl cleansing function is generally acceptable as the water that flows through the rim channel is pressurized. This allows the water to exit the rim holes with higher energy and do a more effective job of cleansing the bowl.

Although rim-jetted bowls are generally superior to non-jetted, the long pathway that the water must travel through the rim to the jet opening dissipates and wastes much of the available energy. Direct-jetted bowls improve on this concept and can deliver even greater performance in terms of bulk removal of waste. In a direct-jetted bowl, the flush water exits the tank through the tank inlet area in the bowl and flows through a manifold. At this point, the water is divided into two portions: a portion that flows through the rim channel with the primary purpose of achieving the desired bowl cleansing, and a portion that flows through a second “direct jet channel” that connects the manifold to a jet opening in the sump of the toilet bowl. The direct jet channel can take different forms, sometimes being unidirectional around one side of the toilet, or being “dual fed,” wherein symmetrical channels travel down both sides connecting the manifold to the jet opening. As with the rim-jetted bowls, the jet opening is sized and positioned to send a powerful stream of water directly at the opening of the trapway. When water flows through the jet opening, it serves to fill the trapway more efficiently and rapidly than can be achieved in a non-jetted or rim jetted bowl. This more energetic and rapid flow of water to the trapway enables toilets to be designed with even larger trapway diameters and minimal bends and constrictions, which, in turn, improves the performance in bulk waste removal relative to non-jetted and rim jetted bowls.

Following are some embodiments of the disclosure.

In a first embodiment, disclosed is flush valve assembly, comprising a flush valve comprising a flush valve body extending from a flush valve inlet to a flush valve outlet; a flapper cover having a top face and a bottom face and a front and a back; and a flush actuator comprising a lift rod; wherein the bottom face of the flapper cover is configured to enclose the flush valve inlet; and wherein the lift rod is coupled to the top face of the flapper cover and is configured to lift the flapper cover to partially open the flush valve and to fully open the flush valve.

In a second embodiment, disclosed is a flush valve assembly according to the first embodiment, wherein the lift rod is configured to lift the flapper cover to partially open the flush valve and to lower the flapper cover to close the flush valve without fully opening the flush valve.

In a third embodiment, disclosed is a flush valve assembly according to the first or second embodiments, wherein the lift rod is configured to lift the flapper cover to partially open the flush valve; to fully open the flush valve; and to lower the flapper cover to close the flush valve.

In a fourth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the lift rod is configured to lift the flapper cover to partially open the flush valve; to fully open the flush valve and to dispose the flapper cover in a position wherein the bottom face is substantially parallel with the flush valve inlet when the flush valve is fully open.

In a fifth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the flapper cover is configured to lift in a peeling motion from the flapper cover front towards the flapper cover back.

In a sixth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the assembly is configured to provide multiple flush volumes.

In a seventh embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the flapper cover comprises a flexible portion. In an eighth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the flapper cover comprises a flexible portion and a rigid portion. In a ninth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the bottom face of the flapper cover comprises a continuous flexible portion. In a tenth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the top face of the flapper cover comprises one or more flexible portions and one or more rigid portions.

In an eleventh embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the lift rod is coupled to the top face of the flapper cover via a multi-arm linkage. In a twelfth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the lift rod is coupled to the flapper cover top face via a pivot arm. In a thirteenth embodiment, disclosed is a flush valve assembly according to embodiment twelve, wherein the pivot arm comprises one or more joints around which the pivot arm may flex. In a fourteenth embodiment, disclosed is a flush valve assembly according to embodiments twelve or thirteen, wherein the pivot arm is coupled to the flapper cover top face front. In a fifteenth embodiment, disclosed is a flush valve assembly according to any of embodiments eleven to fourteen, wherein the multi-arm linkage comprises a pivot arm coupled to the lift rod via an arm extending from the lift rod.

In a sixteenth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the lift rod is coupled to the flapper cover top face via one or more slotted elements.

In a seventeenth embodiment, disclosed is a flush valve assembly according to any of embodiments eleven to sixteen, wherein the multi-arm linkage comprises one or more slotted elements configured to allow movement of one or more arms.

In an eighteenth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the lift rod is coupled to the flapper cover top face via a substantially vertical arm extending from the flapper cover top face. In a nineteenth embodiment, disclosed is a flush valve assembly according to embodiment eighteen, wherein the vertical arm and the lift rod are coupled via a slot-and-pin feature. In a twentieth embodiment, disclosed is a flush valve assembly according to embodiment nineteen, wherein the lift rod comprises a slot and the vertical arm comprises a pin adapted to couple to the slot. In a twenty-first embodiment, disclosed is a flush valve assembly according to embodiment nineteen, wherein the vertical arm comprises a slot and the lift rod comprises a pin adapted to couple to the slot.

In a twenty-second embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the lift rod is substantially perpendicular to the flapper cover face. In a twenty-third embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the lift rod is coupled to the flapper cover top face towards the center of the top face.

In a twenty-fourth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the flapper cover top face back comprises an element configured to couple with an arm extending from the flapper cover top face front. In a twenty-fifth embodiment, disclosed is a flush valve assembly according to embodiment twenty-four, wherein the element is configured to couple with the arm extending from the cover top face front via a slot-and-pin feature. In a twenty-sixth embodiment, disclosed is a flush valve assembly according to embodiment twenty-four, wherein the element comprises a slot and the extending arm comprises a pin. In a twenty-seventh embodiment, disclosed is a flush valve assembly according to embodiment twenty-four, wherein the element comprises a pin and the extending arm comprises a slot.

In a twenty-eighth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the lift rod is associated with a guide element adapted to guide a lifting or lowering movement of the rod. In a twenty-ninth embodiment, disclosed is a flush valve assembly according to embodiment twenty-eight, wherein the guide element comprises a tubular body within which the lift rod is disposed. In a thirtieth embodiment, disclosed is a flush valve assembly according to embodiments twenty-eight or twenty-nine, wherein the guide element is coupled to the flush valve body.

In a thirty-first embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the assembly comprises a first stop element configured to provide a lift end-point of the flapper cover. In a thirty-second embodiment, disclosed is a flush valve assembly according to embodiment thirty-one, wherein the first stop element is substantially ring-shaped. In a thirty-third embodiment, disclosed is a flush valve assembly according to embodiments thirty-one or thirty-two, wherein the first stop element is coupled to the flush valve body. In a thirty-fourth embodiment, disclosed is a flush valve assembly according to any of embodiments thirty-one to thirty-three, wherein the first stop element is coupled to the guide element. In a thirty-fifth embodiment, disclosed is a flush valve assembly according to any of embodiments thirty-one to thirty-four, wherein the first stop element is coupled to the flush valve body and/or the guide element via one or more vertical arms. In a thirty-sixth embodiment, disclosed is a flush valve assembly according to any of embodiments thirty-one to thirty-five, wherein the first stop element is adapted to guide the flapper cover to a position wherein it is substantially parallel with the valve inlet and substantially perpendicular with the lift rod. In a thirty-seventy embodiment, disclosed is a flush valve assembly according to any of embodiments thirty-one to thirty-six, wherein the first stop element is from about 2.5 cm to about 5.2 cm above the flush valve inlet.

In a thirty-eighth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the assembly comprises a second stop element disposed on the flapper cover top face. In a thirty-ninth embodiment, disclosed is a flush valve assembly according to embodiment thirty-eight, wherein the second stop element is disposed towards the flapper cover front. In a fortieth embodiment, disclosed is a flush valve assembly according to any of embodiments thirty-one to thirty-nine, wherein the first stop element is configured to engage the second stop element. In a forty-first embodiment, disclosed is a flush valve assembly according to embodiment forty, wherein the first and/or the second stop element comprise a feature adapted to engage the other. In a forty-second embodiment, disclosed is a flush valve assembly according to embodiment forty-one, wherein the feature comprises a groove-and-ridge.

In a forty-third embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the valve body inlet is substantially circular in shape. In a forty-fourth embodiment, disclosed is a flush valve assembly according to any of embodiments one to forty-two, wherein the flush valve body inlet comprises a shape selected from triangular, rectangular, square, oval, oblong, ovate, elliptic, obovate, cuneate, deltoid or orbicular.

In a forty-fifth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the flush valve body comprises a lead-in lip.

In a forty-sixth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the assembly does not include a back-flow preventer mechanism.

In a forty-seventh embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the flush valve inlet is radiused. In a forty-eighth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the flush valve body is downwardly-tapered. In a forty-ninth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the flush valve body is non-symmetrical.

In a fiftieth embodiment, disclosed is a flush valve assembly according to any of the preceding embodiments, wherein the flush actuator is associated with an electric motor, a hydraulic cylinder, a manual lever, a push button, or a combination thereof.

In a fifty-first embodiment, disclosed is a toilet comprising the flush valve assembly according to any of the preceding embodiments. In a fifty-second embodiment, disclosed is a toilet according to embodiment fifty-one, wherein the toilet is a gravity powered toilet. In a fifty-third embodiment, disclosed is a toilet according to embodiments fifty-one or fifty-two, wherein the toilet is a non-jetted, rim jetted, or direct jetted gravity powered siphonic toilet.

In a fifty-fourth embodiment, disclosed is a flush valve, comprising a flush valve body extending from a flush valve inlet to a flush valve outlet, wherein the valve inlet comprises a shape selected from triangular, rectangular, square, oval, oblong, ovate, elliptic, obovate, cuneate, deltoid or orbicular.

In a fifty-fifth embodiment, disclosed is a flush valve, comprising a flush valve body extending from a flush valve inlet to a flush valve outlet, wherein the flush valve inlet comprises a lead-in lip.

In a fifty-sixth embodiment, disclosed is a flush valve, comprising a flush valve body extending from a flush valve inlet to a flush valve outlet, wherein the flush valve body is non-symmetrical.

In a fifty-seventh embodiment, disclosed is a flush valve according to embodiments fifty-five or fifty-six, wherein the valve inlet comprises a substantially circular shape.

In a fifty-eighth embodiment, disclosed is a flush valve according to embodiments fifty-five or fifty-six, wherein the valve inlet comprises a shape selected from triangular, rectangular, square, oval, oblong, ovate, elliptic, obovate, cuneate, deltoid or orbicular.

In a fifty-ninth embodiment, disclosed is a flush valve according to any of embodiments fifty-six to fifty-eight, wherein the valve inlet comprises a lead-in lip. In a sixtieth embodiment, disclosed is a flush valve according to any of embodiments fifty-four to fifty-nine, wherein the flush valve body is downwardly-tapered.

In a sixty-first embodiment, disclosed is a flush valve assembly comprising a flush valve according to any of embodiments fifty-four to sixty and a flapper cover having a top face and a bottom face and a front and a back, wherein the bottom face of the flapper cover is configured to enclose the flush valve inlet to form a seal when the valve is in a closed position.

In a sixty-second embodiment, disclosed is a flapper cover having a top face and a bottom face, and a front and a back, wherein the flapper cover is configured to form a seal with the flush valve inlet of embodiment sixty-one, and wherein the flapper cover comprises a shape selected from triangular, rectangular, square, oval, oblong, ovate, elliptic, obovate, cuneate, deltoid or orbicular.

In a sixty-third embodiment, disclosed is a toilet comprising the flush valve assembly according to embodiment sixty-one.

In a sixty-fourth embodiment, disclosed is a toilet according to embodiment sixty-three, wherein the toilet is a gravity powered toilet. In a sixty-fifth embodiment, disclosed is a toilet according to embodiments sixty-three or sixty-four, wherein the toilet is a non-jetted, rim jetted, or direct jetted gravity powered siphonic toilet.

Features described in connection with one embodiment of the disclosure may be used in conjunction with other embodiments, even if not explicitly stated above.

The term “coupled” means that an element is “attached to” or “associated with” another element. Coupled may mean directly coupled or coupled through one or more other elements. An element may be coupled to an element through two or more other elements in a sequential manner or a non-sequential manner. The term “via” in reference to “via an element” may mean “through” or “by” an element. Coupled or “associated with” may also mean elements not directly or indirectly attached, but that they “go together” in that one may function together with the other.

The term “towards” in reference to a of point of attachment, may mean at exactly that location or point or, alternatively, may mean closer to that point than to another distinct point, for example “towards a center” means closer to a center than to an edge.

The term “like” means similar and not necessarily exactly like. For instance “ring-like” means generally shaped like a ring, but not necessarily perfectly circular.

The articles “a” and “an” herein refer to one or to more than one (e.g. at least one) of the grammatical object. Any ranges cited herein are inclusive. The term “about” used throughout is used to describe and account for small fluctuations. For instance, “about” may mean the numeric value may be modified by ±0.05%, ±0.1%, ±0.2%, ±0.3%, ±0.4%, ±0.5%, ±1%, ±2%, ±3%, ±4%, ±5%, ±6%, ±7%, ±8%, ±9%, ±10% or more. All numeric values are modified by the term “about” whether or not explicitly indicated. Numeric values modified by the term “about” include the specific identified value. For example “about 5.0” includes 5.0.

The term “substantially” is similar to “about” in that the defined term may vary from for example by ±0.05%, ±0.1%, ±0.2%, ±0.3%, ±0.4%, ±0.5%, ±1%, ±2%, ±3%, ±4%, ±5%, ±6%, ±7%, ±8%, ±9%, ±10% or more of the definition; for example the term “substantially perpendicular” may mean a 90° perpendicular angle may mean “about 90°”. The term “generally” may be equivalent to “substantially”.

All U.S. patent applications, published patent applications and patents referred to herein are hereby incorporated by reference. 

1. A flush valve assembly, comprising a flush valve comprising a flush valve body extending from a flush valve inlet to a flush valve outlet; a flapper cover having a top face, a bottom face, a front, and a back; and a flush actuator comprising a lift rod; wherein the bottom face of the flapper cover is configured to enclose the flush valve inlet, and the lift rod is coupled to the top face of the flapper cover and is configured to lift the flapper cover to partially open the flush valve and to fully open the flush valve.
 2. The flush valve assembly according to claim 1, wherein the flapper cover is configured to lift in a peeling motion from the flapper cover front towards the flapper cover back.
 3. The flush valve assembly according to claim 1, wherein the assembly is configured to provide multiple flush volumes.
 4. The flush valve assembly according to claim 1, wherein the flapper cover comprises a flexible portion and a rigid portion.
 5. The flush valve assembly according to claim 1, wherein the lift rod is coupled to the flapper cover top face via a multi-arm linkage.
 6. The flush valve assembly according to claim 5, wherein the multi-arm linkage comprises a pivot arm coupled to the flapper cover top face.
 7. The flush valve assembly according to claim 6, wherein the pivot arm comprises one or more joints around which it may flex.
 8. The flush valve assembly according to claim 5, wherein the multi-arm linkage comprises one or more slotted elements configured to allow movement of one or more arms.
 9. The flush valve assembly according to claim 5, wherein the multi-arm linkage comprises a substantially vertical arm extending from the flapper cover top face and coupled to the lift rod.
 10. The flush valve assembly according to claim 5, wherein the multi-arm linkage comprises an arm extending from the flapper cover top face front which is configured to couple to the flapper cover top face back.
 11. The flush valve assembly according to claim 1, wherein the lift rod is associated with a guide element adapted to guide a lifting or lowering movement of the rod.
 12. The flush valve assembly according to claim 1, wherein the flush valve body comprises a substantially circular flush valve inlet.
 13. The flush valve assembly according to claim 1, wherein the flush valve body comprises a non-circular flush valve inlet.
 14. The flush valve assembly according to claim 1, wherein the flush valve body comprises a radiused flush valve inlet.
 15. The flush valve assembly according to claim 1, wherein the flush valve body is downwardly-tapered.
 16. The flush valve assembly according to claim 1, wherein the assembly comprises a first stop element configured to provide a lift end-point of the flapper cover.
 17. The flush valve assembly according to claim 16, wherein the first stop element is substantially ring-shaped and is coupled to the flush valve body.
 18. The flush valve assembly according to claim 16, wherein the first stop element is adapted to guide the flapper cover to a position wherein it is substantially parallel with the valve inlet and substantially perpendicular with the lift rod.
 19. The flush valve assembly according to claim 16, wherein the assembly comprises a second stop element coupled to the flapper cover top face.
 20. The flush valve assembly according to claim 19, wherein the first stop element is configured to engage the second stop element. 